Apparatus for and method of vulcanizing tire casings and inner tubes



Aug, 9, 1932- H. A. DENMIRE APPARATUS FOR AND METHOD OF VULCANIZING TIRE CASINGS AND INNER TUBES 7 Filed April 50, 1927 INVENTOR Harold Rheum-ire BY 6110M A W ATTORNEYS Patented Aug. 9, 1932 UNIT STATES P TENT-f wer HAROLD A. DENMIRE, or AKRDhT; oHIo, nssrenonfro mrrnenlvnnnn fr'ire.it-a

COMPANY, or. AKRON, onrog-n CORPORATION" or orI Io APPARATUS FOR AND METHOD: OF VULCANIZING TIRE UASING S Application filed April 30,

This invention relates to. the vulcanization of inner tubes and tire casings and: it

- tire ,casing in the same molding cavity whereby the inner tube'andtire casing are each given the desired smooth surfacefinish.

Another object ofthe'inventlon is to. provide an improved iiorm ofair bag for use,

in, vulcanizingiire casings.

An additional lob ect of the nvention 1s to provide an. mproved method-of vulcaniz ing inner tubes that gives thetubes increased toughness and. improved wearing qualities. v Other objects of the invention willbeap-. parent to those skilled in theartfroma consideration cram accompanying drawing wherein: g Y. I Figure l is. a transverse, :'CIOSS-.;S6Ct10113tl view of an assembled mold, tire casing air.

V of the uncured rubberslab used-in formin the airbag; and I 7 valve of the inner tube bag, and inner. tube being vulcanized.

1 Fig. 2 is. a corresponding crosssectional view of the assembly shown in]? lj the section being taken tllITOLlgh ';th6 inflation Fig. 3 is a transverse, cross sectional view of the mold forthe air bag and the core .mem: ber used in connection therew th.

- Fig. 4 is a detailed viewincrosssection with parts broken away, of the air bag after 35 f vulcanization. v n

- F 1g; 5 1s a transverse, cross sectlonal v ew Fig. 6 is a detailed sectional view of the] air bag showing one of the interlockingfa'sa teners carried by the cooperatingtonguepor tions of the bag. v i. l:

The mold assembly shown in Fig. 1 and Fig. 2 comprises a pair of mated mold sections 1 and 2 and a bull ring 3 that together define a molding cavity wherein a tire casing 4 is being vulcanized vwhilesubjected,

to inflation pressure from an uncured inner tube 5 that is also being vulcanized, and an tube 5 and. thetire casingc. lnfiation presi sures of more than; one hundred pounds; per

square inch 'arepreferably used in order to i pbtain a denseand improved texture of side wall. in the tube. Carbon dioxide gas or .other inert gas is preferably used astliefim fiating medium in orderto avoid oxidation the use of air at these high pressures; The mold sectional and, 2 and the bullying 3 are of conventional design. In accordance With the present. invention the inflation presof the rubber which sometimes results-with i Su fer t e tire ingiwb eine yinfiae 'r n i inn -tub 5=Wifihi1 thea r h s or Cover 6 l eh-enca eshe -i ne stube. lhe air bag 6' not only eonstitutesa mediumjfor'.

e'Xpandingthe pneumatic tire casing: but it also constitutes armold for the-outer. facewof 9:

the inner tube,5 .f'llheairbag6 is formedaf cha'racter ofrubber that will withstand the repea-ted heats 'of vulcanization and-that will also vvithstandthe eflfects of sulphur-mi; gration from thecontacting sur'facesot the innertube 5 ,,and.the tire casing i. 'ilit-isaprefe erably fOIfLnGd-Jyitll an outerand inner molding surface of high aluminum metal bronze v content in ;aeeordance with my copendingap;

around its entire circumference iii-order that l the :innerptube. may readily ibefpositioned I therein.- An annular laterally extendingrih that seats in acorresponding groove formed n the portion 8 of theba'g'serves to-assist lin interlockinggthe two side portions against radial misalignment and also serves to pro vide asmooth surface forwtheinner" face of y the tube. L; The interlocking portions .7 land 8 are desired although they are not essential;

v and; the character offsplit in the tongue of the" air bagmay be II1QClifiB"d' Without departing from the sp rit and scope ofthe inventionv which consists primarily. in interposing:

suitably 'surfacedmember between the inner tube and the tire casing. The contacting faces? oflthe portions]? and- 8 are also pro;

9that are vul canizedinto the body of the bag vtide d .With'a series ofjcooperating-:Easteners:

casing After partial inflation of theinner ing.

for the purpose specified. The fasteners '9 are particularly shown in Fig. 6 of the draw- Fig. 3 shows a suitable mold for forming the air bag from a flat sheet of rubber such, for instance, as that shown in Fig. 5. The sheet of rubber as shown in Fig. 5 is prefer ably delivered from an extruding machine substantially in the shape shown although it .may be prepared in any other suitable manher." 'It is then wrapped aboutaisuitable core 10 of the section shown in Fig.3 .after the fasteners 9 have-b en; inserted in}. suitable:

cavities of the core and the unit is placed in a vulcanizing mold. The-outerand inner molding surfaces of the bagare preferably treated with a protecting inte'gume'nt such for instance as the aluminum metal'bronze disclosed inmy aforesaid copending applica tion. An airbag constructed .in this manner 1 has an opening-around its entire inner peripherythrough which. the inner tube may be inserted. It will also have an interlocking annular groove and flange formed in the cooperating parts of the tongueof the bag to facilitate the sealing of the bag around the inner tube when molding pressures are applied.

j The molding faces of the air bag 6 may be provided with suitable markings for transfer to the-inner tube or-the innertube may be marked inany other suitable way;

In using the apparatus described,,the uncured inner tube5 and air bag 6 with itsfast V eners 9 engaged are placed withinthe tire tube the assembly'is placed in a suitable heated mold. The inner tube is then inflated to sufficient degree to expel air from between the inner tube and the bag and also from be. tween thebag and the tire casing. The mold is-then closed and the assembled unit is'sub; j ected to molding heat and pressure. As heretofore stated, carbon dioxide is preferably used to inflatethe inner tube and the inflation pressure increased materially over the inflatio'n pressurecommercially used in the curing of inner tubes at the present time. Any other suitable inflating medium may be used instead of the-above mentioned carbon dioxide. The advantages to be gained by vulcani ze ing tubes and casings in the manner described Will be obvious to those skilled in the art-.1 It will .be apparent that the air bag or tube cover} 6- constitutes a IDOldfOD the inner tube and Y i that the outer face of the bag 6 constitutes a moldorcore for the inner-face ofthe tire casing. When theseunits are-assembled as shown in Fig. 1 and Fig.2 andtheassembled' structure is vulcanized, thejouter "surfaceof *thetube 5 is smooth and thei markings of the bag will be formed on the tube. I v

V of said body together,v

and tube are obtained and the character of the finished tube is greatly improved because of its vulcanization on an inert gas at greatly increased pressures. The expense of using an inert gas is compensated for by the concurrent curing in a single mold unit of both casing and tube and the use of the inexpensive character of air bag proposed.

Although only one application of the in- .ventionis described for illustrative purposes, other modifications thereof willbe obvious to those skilled in the art and I desire, therefore,

that only such limitations shall be imposed on the invention as are presented by the prior art.

' What Iclaimis LThejmethod of concurrently vulcanizing an inner tube 'and'tire casing that con- I sists in assembling the inner tube within the tire casing with a molding member which fits within the tire casing and completely encloses the inner tube, inflating the inner tube with a substantially inactive fluid and vulcanizing the casing and applying heatthereto to'concurrently vulcanize the casing and inner tube. I V 2; An air bag unit liavinga hollow annular bodyof rubber composition, the side wall of said body being cut-completely through around the inner portion thereof for removably receiving therein an inflatable member,

and means for detachablyfastening the edges of saidbody together. I

' 3.1Ajrubber. air bag jof'the character described comprising anf'endless hollowibody' portion. of annular form having its side walls separated by an endlesssplit for the inser fastening theedges 4. An-air of the character described comprising an endless body portionof annular form having its sidewall separated by tion within the bag of an inflatable member, and means forv detach'ably an endless 'split thereinfor the insertion within the bag of an-inflatable member, and a plurality of cooperating fasteners carried by the'engaging portions of said endlesssplit forholding the edgesof. the split together he advantages of-practicing the inven-j' tionwill be apparent tothose skilled in the art. Concurrent vulcanizationofthe casing 

